IMG Parameters Dialog        

IMG Parameters dialog

The IMG Parameters dialog is used to enter information required for interpretation of raw pixel (.IMG) format files. Changes to the parameters must be made before a .IMG file is read.


The number of Rows and Columns, in pixels, stored for each frame in the image. The values must match the layout present in the file.

Pixel Layout

Bits Allocated is the number of bits stored for each pixel; this value must match the layout present in the file. The bits used in obtaining the pixel values are determined from the number of Bits/Pixel and the position of the High Bit, the largest position in the range used. To use the first 8 bits, for example, set Bits/Pixel = 8 and High Bit = 7.

Endian Swap

When Endian Swap is checked, a little endian to big endian swap is applied to each byte of pixel data.

The Pixel Layout box is not present when ICRP 110 is checked.

Dimensions (mm)

The values in the Dimensions box are used for scaling when generating MCNP geometry. The Pixel Width and Height give the size of a pixel in mm. Slice Thickness is the distance between frames in mm.

Contrast Window

Pixel values within the Contrast Window are mapped to intensities between 0 and 255. When Auto is checked, the Center is the average of extreme pixel values found in the file and the Width is the difference of the extremes. Otherwise, explicit Center and Width values can be entered.

Offset (Bytes)
The number of Bytes to skip before reading pixel data. The Offset can be used to bypass header information.


When Use All is checked, all frames in the .IMG file are read and used. If Selective is checked, every nth frame between Start and End are loaded where n is the value of Increment.


When Segmented is checked, the pixel values are interpreted as numbers of identified regions, such as organs in a human scan, rather than image intensities.

ICRP 110

When ICRP 110 is checked, the pixel values are interpreted as numbers of organs and tissues defined in ICRP publication 110. The Pixel Layout box is replaced by a Slices field for entering the total number of vertical slices in the data. Segmented should also be checked.

Auto Read IMD File

When Auto Read IMD File is checked, the image parameters file foo.imd is automatically read before load image file foo.img or foo.dat if it is present in the same directory as the image file.

Floating Point

Under development.

Apply puts the changes into effect and dismisses the dialog.

Cancel dismisses the dialog without changing any settings.

Help shows the help page for the dialog.

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